The invention relates to Stirling engine-equipped cogeneration system of the type, for example, disclosed in Related Art References (Tokkyo bunken) 1 and 2.
Related Art Reference 1 discloses a cogeneration system assembled from a hydrogen storing heat pump and a Stirling engine equipped with an electrical generator wherein the heater part of the Stirling engine includes a heat-generating fuel-combusting burner located at the center of the upper surface of the combustion case, and further includes combustion air passages being located at the upper wall of the combustion case and leading from an external region to the flame orifice of the burner. In this cogeneration system, the thermal energy lost from the burner is 15% of the total (100%) input thermal energy.
Related Art Reference 2 describes a cogeneration system using a composite Stirling and Rankine cycle and driving a compressor that heats low-temperature steam and an electrical generator by the operation of Stirling engine. The heater of the Stirling engine is heated by air fed in from an air inlet port and heated by the combustion operation of the heat-generating burner, said heated air then being applied to a heat exchanging operation with air fed in from the air inlet port.
[Related Art Reference (Tokkyo bunken) 1]: Japanese Patent Laid-open (Kokai) Publication No. H7-279758 [pages 3-5, FIG. 1 and FIGS. 6-8]
[Related Art Reference (Tokkyo bunken) 2]: Japanese Patent Laid-open (Kokai) Publication No. 2000-213418 [pages 3-5, FIG. 1 and FIG. 5]
Both of the above-noted conventional cogeneration systems employ a dedicated heating device to supply thermal energy to the Stirling engine heater, use the output of the Stirling engine to generate electricity from an electrical generator, and also use the obtained thermal energy to drive a hydrogen storing heat pump and compressor through a driving structure, thus they employ a mechanical structure to derive power from thermal energy. This structure wastes a large amount of the thermal energy generated by the thermal source, and therefore these cogeneration systems cannot be said to use thermal energy efficiently.